cheap

A cheap dual band ground plane antenna - This little antenna is cheap and easy to build, lightweight, and very functional on 2 meters and 70 centimeters by NA4IT

4m Slim Jim Antenna - This 4m Slim Jim Antenna is cheap and easy to build yet it greatly out performs the more usual dipole due to its low angle of radiation. An SWR of 1:1 is obtainable across the 4m ham radio FM band with a simple adjustment.

Squid poles as portable multiband antennas - Fancy a cheap, collapsible self-contained portable antenna for 80, 40, 30, 20 and 15m that works really well and can be erected in minutes, by VK7JJ

Rabbit-Ears Dipole Antenna - This handy and cheap portable dipole can be folded and backpacked, carried in use, and adjusted to a very wide range of frequencies.

Cookie Cantenna Wi-Fi - Make a cheap, portable, high performance (15-18 db) directional antenna out of commonly available parts that can be purchased in most grocery and hardware stores.

Elecraft K2 Improving CW Filter - Here is a cheap and simple way to significantly improve the K2 CW filter(s). With this mod, even strong signals will fade to black as they tune out of the filter pass band

HF power amplifier using GI7B - Gi7b is tube designed for microwaves but working good as HF amplifier. Idea is to build cheap, reliable HF amplifier covering 160 meters band.

Using cheap tetrodes in amplifiers - This article is written to dispel some of the misconceptions and misunderstandings about some of the tetrode based linear amplifiers, which are currently available on the amateur market.

A 100 Watt UHF Power Amplifier - Build a 100 Watt power amplifier using cheap, readily available junk radios

A Cheap & Easy 2.4GHz Feed - The KI7CX 2.4 GHz Cheap & Easy antenna/feed

The Milli Beacon - This page describes an cheap RF signal source, a portable micro beacon, using a low cost temperature controlled crystal oscillator

Connectors - There are scores of RF connector types, ranging from the \"cheap and cheerful\" to the extremely expensive types intended for use in professional and military applications.

RF Coaxial Switch - An interesting rf coaxial switch project capable of handling 800-1500 W. This is a cheap home made RF coaxial switch in use by PA0FRI

A Two Meter Duplexer - How to get a cheap-squeaky clean signal, a 2 meter duplexer designed by Leonard WB3AYW

Cheap Crystal Filter - An economical way of building an SSB filter. The circuit is for a filter with a 6 DB band width of roughly 2.2 KHz.

ZL2PD CMOS Keyer - Two cheap CMOS ICs and a few transistors was all that was required to rebuild an elderly TTL automatic morse keyer into a low current lightweight battery powered iambic morse keyer.

40 CW QRP Transmitter  ^new - Here is a easy to build and cheap CW transmitter using 40 m cristals. Power output is approximately 6 Watts for a supply voltage of 13.8 VDC

Sub-Tone Generator for repeater triggering - If you need a cheap and easy to construct Subtone Generator for EU-model VHF-UHF rig, here is a solution that works very well.

rtl-sdr.com A blog about RTL-SDR  ^new - RTL-SDR is a very cheap software defined radio that uses a DVB-T TV tuner dongle based on the RTL2832U chipset. This is a blog about rtl-sdr, software defined radio and their developments and applications.

Build a Test Meter - This article include a circuit that allows a cheap 0-1mA meter to be used as a micro-ammeter or a milli-voltmeter